How to reorder XtraTreeList nodes via drag-and-drop

Description:
Is it possible to use drag&drop to reorder rows?

Answer:
[Updated]
Starting with version 15.2, this functionality is accessible out of the box. To enable it, set the TreeList.OptionsDragAndDrop.DragNodesModeproperty to Single or Multiple.

[For versions older than 15.2]
The attached sample projects demonstrate how to override the default drag&drop handling in an unbound XtraTreeList and allow users to reorder nodes only within a given parent node.
The TreeList has the automatic drag&drop support. You can utilize it without writing additional code. However, some tasks may require you to have control over drag&drop operations. Fortunately, the TreeList provides you with the necessary API for accomplishing such tasks.
In this case, you should use the DragOver event and change the e.Effect parameter, if you need to conditionally enable/disable the drop operation. Set e.Effect to DragDropEffects.None to disable the drop operation. The DragDrop event will not be fired in this case.
The DragDrop event is used to handle dropping an object at a given position. Our sample project utilizes it to move a node to a new location via the SetNodeIndex method of the TreeList class. Finally, the e.Effect parameter should be set to DragDropEffects.None to notify the TreeList of that the drag&drop operation is handled and the default processing is not needed.
To calculate a value for e.Effect, you may need to know which node resides under the mouse cursor. Use the CalcHitInfo method of TreeList for this. Pay attention that screen coordinates are passed to the DragOver and DragDrop events. Before you call CalcHitInfo, you must convert screen coordinates to the TreeList coordinates via the the PointToClient method.

C#
using DevExpress.XtraTreeList;  

using DevExpress.XtraTreeList.Nodes;  



private void treeList1_DragDrop(object sender, System.Windows.Forms.DragEventArgs e) {  

    TreeListNode dragNode, targetNode;  

    TreeList tl = sender as TreeList;  

    Point p = tl.PointToClient(new Point(e.X, e.Y));  



    dragNode = e.Data.GetData(typeof(TreeListNode)) as TreeListNode;  

    targetNode = tl.CalcHitInfo(p).Node;  



    tl.SetNodeIndex(dragNode, tl.GetNodeIndex(targetNode));  

    e.Effect = DragDropEffects.None;  

}  

Visual Basic
Imports DevExpress.XtraTreeList  

Imports DevExpress.XtraTreeList.Nodes  



Private Sub TreeList1_DragDrop(ByVal sender As Object, ByVal e As DragEventArgs) Handles TreeList1.DragDrop  

    Dim dragNode, targetNode As TreeListNode  

    Dim tl As TreeList = CType(sender, TreeList)  

    Dim p As Point = tl.PointToClient(New Point(e.X, e.Y))  



    dragNode = e.Data.GetData(GetType(TreeListNode))  

    targetNode = tl.CalcHitInfo(p).Node  



    tl.SetNodeIndex(dragNode, tl.GetNodeIndex(targetNode))  

    e.Effect = DragDropEffects.None  

End Sub  

See Also:
How to insert a TreeList node into a specific position
How to change XtraTreeList drag-and-drop icons

How to reorder XtraTreeList nodes via drag-and-drop
How to implement drag and drop between two XtraTreeList controls
TreeList.CustomizeNewNodeFromOuterData Event